Backfire at idle? sounds like its missing??
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Teching In
Joined: Jul 2013
Posts: 4
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Backfire at idle? sounds like its missing?? OK I have a 2002 Z28.... has speed inc 228 cam, long tubes, flowmaster exhaust.... m6.... had a tune... I bought a supercharger kit... car ran great before I started this process... installed the kit, with a set of fast 36lb injectors.... started the car and it ran ok... just took it around the block and it was ok also... didn't get on it... next day I started it up and it was missing bad... I also switched the fuel pump to a walbro 340... I decided it was running rich from having the 36lb injectors and no tune for them... pulled them off and put the stock injectors back in... still was missing.... so I thought the plugs could be fouled from the extra fuel... changed the plugs and wires... I also took the supercharger off... so its back to how it was before I ever messed with it... put the factory fuel pump back in also... start the car... same thing but now there is a backfire in the exhaust at idle randomly.... checked that the plug wires were all on correctly and they are all tight.... the plugs I switched out were exactly the same as what I put in.... fuel pressure at the fuel rail looks to be about 58psi.... no codes are being thrown.... what could it be? I am new to the ls1.... could the tune from when they did the cam be lost by disconnecting the battery??? right now I just want it back to how it was before I messed with it lol... any help would be greatly appreciated..
thanks
thanks
If you have it all back to pre upgrade condition and its still behaving that badly, you may have done some real damage by having way too much fuel. Not sure how that could cause a backfire though.
The tune wont be lost from disconnecting the battery.
Any info you get here would just be guessing, but I'd be thinking about a compression test at this point.
The tune wont be lost from disconnecting the battery.
Any info you get here would just be guessing, but I'd be thinking about a compression test at this point.
TECH Resident
Joined: Feb 2007
Posts: 831
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From: Boston, MA
If you have it all back to pre upgrade condition and its still behaving that badly, you may have done some real damage by having way too much fuel. Not sure how that could cause a backfire though.
The tune wont be lost from disconnecting the battery.
Any info you get here would just be guessing, but I'd be thinking about a compression test at this point.
The tune wont be lost from disconnecting the battery.
Any info you get here would just be guessing, but I'd be thinking about a compression test at this point.
flip em..... You installed a bank of injectors harness backward. Likely the problem is on one cylinder bank.
Identify which side is misfiring disconnect the injectors take the harness bar and flip it so the plug that connected the front injector will now be connected to the injector in the back connect the rest the plugs to the injector in front of it, start the engine see if it back to business, come back and tell us if all is good.
Identify which side is misfiring disconnect the injectors take the harness bar and flip it so the plug that connected the front injector will now be connected to the injector in the back connect the rest the plugs to the injector in front of it, start the engine see if it back to business, come back and tell us if all is good.
